Passenger and commercial vehicles use various hydraulic devices such as clutch assemblies, brake assemblies, and valve bodies. A pump provides a fluid to the hydraulic device, and a flow regulator regulates fluid flow from the pump to the hydraulic device. Sensors are used to measure the fluid flow through the hydraulic device and diagnose problems with the flow regulator. Vehicle manufacturers purposely operate hydraulic devices at low fluid pressures at various times because doing so provides benefits such as increased efficiency. These low pressures, however, are often too low to be detected by the sensors. Therefore, the sensor is not always able to detect fluid flow through the hydraulic device. Without the ability to detect fluid flow, a flow regulator failure may go undetected by the sensor.